Method of treating coated materials



latented Dec. 15,

UNITED STATE EDGAB CORNELL, JR, OF FITTSBURGI I, PENNSYLVANIA, AS SIGNOB TO WESTING- HOUSE ELECTRIC & VANIA.

No Drawing.

To all whom it may concern."

Be it known that I, EDGAR CORNELL, Jr., a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new' and useful Improvement in Methods of Treating Coated Materials, of which the .following is a specification.

This invention relates to coated materials, more particularly to metal articles coated with zinc or the like.

Heretofore, it has been customary to coat .metal articles, which are intended to be exposed to atmospheric conditions, with zinc or like materials by one of several processes, such as electro-galvanizing, hot galvanizing or sherardizing. tle and had a tendency to peel or flake, ofi', owing to the crystalline structure of the zinc. This was the case regardless of the method of deposition of the coating, but ordinarily this defect was not detrimental to the article because the coating operation was the last before placing the article in sery'ice. However, it often; occurs that after coating the article, it is necessary to work the same, as by bending, rolling, drawing or hammering, and in such case the coating peeled off to a large extent, thus greatly reducing the protective value th'ereo.

My inventionis intended to obviate this disadvantage, it being the objects thereof to provide a method of treating zinc coated materials, which shall prevent the peeling or flaking off of the zinc.

' In practicing my invention, I take advantage of the fact that at elevated temperatures zinc is no longer brittle, but becomes malleable, and I have found that between the temperatures 100 C. and 200 C., zinc is sufliciently malleable so that it may be worked. I, therefore, provide a zinc coated article and heat the same to a tem erature somewhat above 100 C.,'whereby t e grain structure of the zinc coating isaltered and the zinc is rendered malleable. The article is then worked at the. elevated temperature.

whereby the character of the zinc coating is permanently changed and rendered malleable when cold. The danger of flaking oil of the coating is obviated since the zinc by the heating and hot working has been rendered permanently malleable.

A- specific example of the operation of MANUFACTURING COMPANY, A CORPORATION a hot' galvanized coating thereon.

he zinc coatingwas brit- OF PENNSYL- METHOD OF TREATING COATED MATERIALS.

Application filed December 21, 1928. Serial No. 692,108;

my invention is as follows: In the production of wood strain insulators, I provide a pair of metal caps which are first cleaned and thendipped in molten zinc to provide coated caps are then immersed in a bath of acid-free oil heated to a temperature of about 135 C. for a sufiicient length of time to allow the ca s to attain the temperature of the bath. hey are then removed and fitted onto the ends of a treated wood rod I and swaged in place.

I have found that I may swage bendsin the caps of 45? without any injury whatsoever to the coating. The coating is not only malleable when hot, but also. after cooling, and therefore the articles .worked'in accordance with my invention may afterwards be handled roughly and thrown about without injury to the coating. I

Although I have described my invention setting forth a specific embodiment thereof, various changes in the details of my invention may be. made within the scope thereof.

For instance, my method may be applied to galvanized wire, strap, and the like, which may be subsequently drawn either hot or cold, and also to castings which are subsequently to be stamped or swaged. It is not necessary that the working of the material take place while hot, as good results may be obtained by working the articles after cool- .ing, if the grain structure of the zinc has previously been changedv by working the articles hot. These and other changes may be made inmy invention without departing from the spirit and scope thereof.

I claim as my invention:

1. A method of treatin zinc coated materials which comprises heating the same to a temperature sufiicient to change the grain structure pf the zinc and then working the material.

2. A method of treating zinc coated materials which comprises eating the same to a temperature above 100 C. and then 7 working the material thereby rendering the coating malleable when cold. i

3. A method of treating zinc coated materials which comprises heating the same to atemperature between 100 C. and 200 C..

thereby rendering the coating -malleable when cold.

The

4. A method of treating zinc coated ma terials which comprises heating the same to a temperature between 100 (Land 200 C. and thenworking the material.

A methqd of treating zinc coated ma- 5 'terials which Comprises heating the same to a temperature above 100 G. and then working the material at said temperature.

6. A method of treating zmc coated macember, 1923..

'teriels which comprises heating the same to a, temgemtme between 100? C. and 200 (3.

In testimony whereof, I have hereunto subscnbefi my name this 14th day of De- EDGAR CORNELL, 33. 

